A better question is what books one would leave for aliens to discover, assuming such aliens are intelligent and can engage in a bit of "radical interpretation":
On the Origin of Species by Some Dude
The latest edition of a quality mathematics textbook
The latest edition of a quality physics textbook
The latest edition of a quality linguistics textbook
The Language of Thought by Jerry Fodor
In other words, it would be a grab bag of our latest scientific understanding of the world to show that we weren't complete retards (since most of whatever else the aliens find will indicate as such). The first two will be a point of contact between the aliens and us, since presumably evolution via natural selection occurs on other planets, and because presumably mathematics is universal (though the aliens will probably use something other than base ten).